Ok, let me start by saying I'm sorry if this has been addressed several times before. That being said, I've recently started work on a property that uses several battery operated controllers, namely the old irritrol IBOC. I've never worked with these before, and I have a few questions about trouble shooting. I have a few zones stuck open and a few that don't come on at all. Normally when I encounter valves that are stuck open, I take the valve apart, replace the diaphragm, and for a few bucks in parts and a few minutes of time, the problem is solved. I'm not sure if this will hold with valves with the DC latching solenoids. I know these get a signal to open, and then another to close. Do these solenoids tend to fail in a way where they don't close, or should I still be thinking diaphragm first? Is there anyway to tell with these solenoids if they are opening and closing properly? Any general info or trouble shooting suggestions/differences when using these systems would be very much appreciated. Thanks.